1. Field of the Invention
This invention relates to confocal microscopic equipment which can measure the confocal image of a sample at high speed; and more particularly, to such equipment which does not require scanning of an irradiating light beam.
2. Description of the Prior Art
The confocal microscopic equipment has a resolution in the direction of the light axis and a resolution on the surface of a smaple by scanning an irradiating light beam on the sample and detecting the light beam reflected from the sample through pinholes or the like. FIG. 1 shows an example of such a conventional confocal microscopic equipment, wherein the output light beam of laser 1 is transmitted through beam splitter 2 and is focused on sample 7 via mirror scanners 3 and 4, and objective lens 6. The return light, including reflected light, fluorescent light, etc, from sample 7, is made to be incident on beam splitter 2, via objective lens 6, mirror 5, and mirror scanners 4 and 3. The return light is reflected by beam splitter 2, passed through pinholes 8 and is made incident on detector 9.
The output light beam from laser 1 is focused at a point on sample 7 by means of objective lens 6. By detecting the return light, resulting from the output light beam from laser 1 focused at a point on sample 7 via pinhoes 8, a confocal effect is obtained. That is, a point in the three dimensional space can be precisely observed. Furthermore, a confocal image of the surface of sample 7 is obtained by scans in the x-axis and y-axis directions on the surface of sample 7 using mirror scanners 3 and 4. As a result, it is possible to obtain a confocal image by scanning the focused light on sample 7 using mirror scanners 3 and 4 and detecting the return light through pinholes 8.
FIG. 2 shows another conventional confocal microscopic equipment, such as disclosed in Japan Unexamined application SN 93/60980, wherein the output light beam from laser 1a is made to be incident on micro-lens disk 10, wherein micro-lenses are provided as a focusing means. The output light mean is then focused on each pinhole in disk 12, wherein the pinholes are provide as apertures, via beam splitter 11, which is a light branching means, by micro-lenses provided in disk 10. The light beam, that passes through the pinholes in disk 12, are made to be incident on sample 14, via objective lens 13. The return light beam, such as reflected light and fluorescent light, from sample 14 are made to be incident again on pinhole disck 12 via objective lens 13. The incident light beams that pass through each pinhole in the disk 12, are reflected by beam splitter 11, and are made to be incident on detector 16 via relay lens 15. In addition, micro-lens disk 10 and pinhole disk 12 are fixed on the same shaft and are rotated synchronously by motor 17 attached to the shaft.
The output of laser 1a scans the surface of sample 14 by passing through the micro-lenses in disk 10 and pinholes in disk 12, both disks being rotated concurrently. The reflected light beams from sample 14 are detected by detector 16 and thus a confocal image is obtained thereby.
Each micro-lens in disk 10 focuses the incident light beams on each pinhole of disk 12 via beam splintter 11. That is, the efficiency of use of the incident light beam from laser 1a is improved by arranging the pinholes at the focal points of the micro-lenses. In addition, there are approximately 1,000 pinholes in the detectable range, i.e. the field of view, of the detector 16. Hence, light beams transmitted through each pinhole constitute multi-beams that irradiate sample 14. Since individual beam scanning ranges become smaller for this reason, high speed scanning becomes possible.
However, disadvantageously, in the example of FIG. 1, the configuration of mirror scanners 3 and 4 of the scanning means is complex, thereby resulting in an expensive apparatus, and making miniaturization thereof difficult. Although the example of FIG. 2 can scan at high speed, since a definite distance exists between the beams, disadvantageously, beam scanning is necessary for covering the distances on a confocal image, and the time required for such beam scanning limits the pickup speed for confocal images. For example, it takes about 1 ms to scan one confocal image. Thus, a confocal image cannot be picked up within 1 ms even when a high speed camera is used.